Which of the following could NOT be a delta-neutral portfolio?

A. A long position in call options plus a short position in the underlying stock
B. A short position in call options plus a short position in the underlying stock
C. A long position in put options and a long position in the underlying stock
D. A long position in a put option and a long position in a call option

B

Calls have a positive delta. Puts have a negative delta. A long stock position has a positive delta. A short stock position has a negative delta. B cannot be delta neutral (i.e., have a delta of zero) because both parts of the portfolio have a negative delta.